There are two methods that you can use to hopefully save your profile if you're hacking or modding or whatever it is that you do with your game.

Method 1: The Cloud Save

This is a really easy method, specifically created for RR3 by FM and built into the game. Just go into the settings and navigate to the cloud save screen. You can either restore from the cloud or save to the cloud, and this will restore all of your data from the last time you cloud saved. This is the better method to do, unless you're doing something that could mess with your game center account or other data online. In this case, you should go for the second method.

Method 2: iFunBox File backup

Download iFunBox online. Plug your device into your computer and open up iFunBox. Navigate to the installed apps folder and find Real Racing 3. Then grab the Documents folder from the Real Racing 3 App Data and save to your computer. In this method, all of the Real Racing 3's app data is saved directly to your computer. When you need to restore, just open back up iFunbox and copy all the data back into RR3's app data. Your profile should be exactly how you left it! Hope this helps people :)